A Remote Sensing-Based Approach to Identifying Spatio-Temporal Changes in Coastal Morphology in Bhola District, Bangladesh

Abstract

Bhola, the largest island of Bangladesh located at the estuarine mouth bar of the Bay of Bengal is very dynamic and unique in nature due to its physiographical configurations and is experienced severe morphological i.e. erosion- accretion changes. Of late, monitoring of coastal morphology and changes in shoreline trend analysis has conveniently been done through the integration of remote sensing satellite imageries and GIS techniques. The present study is an endeavor to detect and analyze the morphological changes on Bhola Island. Multi-temporal satellite images are the main data sources to attain the objectives through the integration of RS and GIS. The study concludes from the recent 42 years (1974- 2016) satellite data that- the Island is in the losing phase since 1974. The erosion processes are still active along the eastern and northeastern parts of Bhola Island due to the direct influence of the Meghna Estuary on the land by the steep bank slope, high tidal water pressure, and loose bank materials. Erosion is the burning issue on Bhola Island and due to this a large number of people are landless every year. On another side, accretion is being operated in a large part surrounding the Island increasingly in the southern part due to backwash sediment deposition by channel and estuary with the favor of a gentle topographic slope along the bank.